1. Field of the Invention
The present invention relates to a recording media for use in a recording media for a sublimation-type heat-sensitive transfer recording process, in particular for increasing the whiteness degree therein.
2. Description of the Related Art
A sublimation-type heat sensitive transfer recording process is characterized by a low noise output, small-sized, low priced apparatus having a short output time and which is easily conserved. In addition, as a result of using a sublimable type disperse dye, high gradation recording characterized by such qualities as a high density and a high definition can be carried out by means of continual fluctuation of the heat generating energy amount. As a result in comparison with other recording processes, it is particularly advantageous in obtaining blue color copies. Accordingly, it is widely employed as the recording process in color printers, video printers, and the like.
As the image-receiving layer of the recording media for use in sublimation-type heat-sensitive transfer recording processes, a dyeable resin composed principally of a polyester resin which is thermally cured using a reactive silicon, as disclosed in Japanese Patent Application Kokai 61-106293, and a dyeable resin also composed mainly of a polyester resin which is cured by means of a crosslinking agent cured with active energy rays, as disclosed in Japanese Patent Application Kokai 63-67189, have been employed.
Recently, there has been wide adoption of video printers for public use on the market along with a user demand for image receiving paper with a high foundation whiteness degree in comparison with photo prints. As a means for increasing the whiteness degree of the recording media, a process is known, as disclosed in Japanese Patent Application Kokai 61-237693, in which white pigments such as titanium oxide and the like in the image-receiving layer are refined, and in which the addition of fluorescent whitening agents to the image-receiving layer is carried out.
However, in this process, as a result of introducing the white pigment inorganic particles into the image-receiving layer, minute projections and indentations are formed on the image-receiving layer surface upon curing, which in turn exert harmful effects on the recording image. For example, although an outlined image is provided, there exist problems in that it is difficult to uniformly disperse the white pigment on the image-receiving layer coat. In addition, in the case when using a fluorescent whitening agent, the existence stability of the image-receiving layer becomes damaged by addition of the fluorescent whitening agent, namely, the image-receiving layer turns yellow from the light and heat. Furthermore, there exists a drawback in that due to the comparatively high cost of the fluorescent whitening agent, its addition results in a similar increase in the cost of the image-receiving paper. Similarly, in the case when curing the image-receiving layer with active energy rays, due to the powerful energy, there exists a problem in that the image-receiving layer turns yellow following changing of the white pigment to a yellow color and decomposition of the fluorescent whitening agent.